Filled polymer compositions

ABSTRACT

A filled polymer composition which comprises 
     (A) from about 5 to about 90 percent of one or more thermoplastic substantially random interpolymers prepared by polymerizing one or more α-olefin monomers with one or more vinylidene aromatic monomers and/or one or more hindered aliphatic or cycloaliphatic vinylidene monomers, and optionally with other polymerizable ethylenically unsaturated monomer(s), and 
     (B) from about 10 to about 95 percent of one or more inorganic fillers, 
     the amounts of (A) and (B) being based on the total weight of (A) and (B). 
     Fabricated articles made from the filled polymer compositions are useful as sound insulating or energy absorbing films or sheets or as floor, wall or ceiling coverings.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

BACKGROUND OF THE INVENTION

This invention relates to filled α-olefin/vinylidene monomerinterpolymer compositions, and fabricated articles thereof.

Fillers are frequently used to improve the stiffness of polymercompositions, or to decrease the coefficient of linear thermalexpansion, or to decrease the overall cost of the polymer composition.However, such fillers are well known to simultaneously decrease impactperformance or toughness of the resultant composition. For example,Joseph A. Randosta & Nikhil C. Trivedi in Talc [published in Handbook ofFillers and Reinforcements for Plastics 160 (Harry S. Katz & John V.Milewski eds.)] confirm that the impact performance of polymericmaterials is generally decreased by the presence of rigid fillers,especially below the glass transition temperature (Tg) of the matrixmaterial, due to the fillers' action as "stress concentrators".

Typically, the filler is incorporated at levels ranging from 1 to 50weight percent of the formulation, depending upon the filler density.Furthermore, even at relatively high levels of filler loading (e.g.,greater than about 20 percent), typical thermoplastic formulations(e.g., polypropylene, an elastomeric rubber and talc) have very poorimpact performance and do not function well in uses such as automotivefacia. Low temperature impact resistance generally becomes more criticalwhen the formulation is exposed to temperatures approaching the glasstransition temperature of the rubber used in the formulation. Sometimesthe room temperature impact resistance may even increase for highlyfilled formulations, but the low temperature impact resistance decreasesrapidly with decreasing temperature.

The patent application WO 95/09945 discloses a thermoset elastomercomposition which comprises a cross-linked substantially randominterpolymer of (a) 15 to 70 weight percent of an α-olefin, (b) 30 to 70weight percent of a vinylidene aromatic compound and (c) 0 to 15 weightpercent of a diene. The linked substantially random interpolymer istypically mixed with a filler, an oil, and a curing agent at an elevatedtemperature to compound them. The amount of the curing agent istypically from about 0.5 to 12 weight percent, based on the total weightof the formulation. Carbon black may be added in an amount of up to 50weight percent, based on the total weight of the formulation, to maskthe color, to increase the toughness and/or to decrease the cost of theformulation. The disclosed thermoset formulations are useful in hoses,air ducts, brake cups, roofing materials and as various automotiveparts, such as tires and moldings. However, the post-extrusion curingresults in a cross-linked thermoset part that can not be reprocessed asa thermoplastic. This limits recyclability of the product.

U.S. Pat. No. 5,576,374 discloses filled thermoplastic olefiniccompositions which have good low temperature impact performance andmodulus. They comprise

(A) a thermoplastic resin selected from the group consisting ofthermoplastic polyurethanes, polyvinyl chlorides, styrenics, engineeringthermoplastics, and polyolefins,

(B) at least one substantially linear ethylene/α-olefin polymer which ischaracterized as having:

a) a melt flow ratio, I₁₀ /I₂, ≧5.63,

b) a molecular weight distribution, M_(w) /M_(n), defined by theequation: M_(w) /M_(n) ≦(I₁₀ /I₂)-4.63, and

c) a critical shear rate at onset of surface melt fracture of at least50 percent greater than the critical shear rate at the onset of surfacemelt fracture of a linear ethylene /α-olefin polymer having about thesame I₂ and M_(w) /M_(n), and

(C) at least one filler.

The filled thermoplastic olefinic compositions are said to be useful asautomotive bumpers, facia, wheel covers and grilles and freezercontainers.

In view of the wide ranges of desirable properties and uses forthermoplastic polymers, it would be desirable to provide new filledpolymer compositions.

SUMMARY OF THE INVENTION

In one aspect, the present invention relates to a filled polymercomposition which comprises

(A) from about 5 to about 90 percent of one or more thermoplasticsubstantially random interpolymers prepared by polymerizing one or moreα-olefin monomers with one or more vinylidene aromatic monomers and/orone or more hindered aliphatic or cycloaliphatic vinylidene monomers,and optionally with other polymerizable ethylenically unsaturatedmonomer(s), and

(B) from about 10 to about 95 percent of one or more inorganic fillers,the amounts of (A) and (B) being based on the total weight of (A) and(B).

In another aspect, the present invention relates to a fabricated articlemade from such filled polymer composition.

In yet another aspect, the present invention relates to a multilayeredstructure wherein at least one layer is made from such filled polymercomposition.

DETAILED DESCRIPTION OF THE INVENTION

It has been surprisingly found that thermoplastic substantially randominterpolymers which have been prepared by polymerizing one or moreα-olefin monomers with one or more vinylidene aromatic monomers and/orone or more hindered aliphatic or cycloaliphatic vinylidene monomers,and optionally with other polymerizable ethylenically unsaturatedmonomer(s) can be blended with high levels of one or more inorganicfillers and that fabricated articles made from filled polymercompositions comprising one or more of such thermoplastic interpolymersand one or more inorganic fillers in the above-mentioned weight ratioshave a substantially improved hardness and tensile modulus whilegenerally maintaining good elongation properties, such as strain atbreak, stress at break and energy at break, as compared to fabricatedarticles made from a corresponding thermoplastic interpolymer withoutinclusion of a filler.

It has also been surprisingly found that fabricated articles made fromfilled polymer compositions which comprise one or more of suchthermoplastic interpolymers and one or more inorganic fillers in theabove-mentioned weight ratios often have a better scratch resistancethan filled thermoplastic olefinic compositions disclosed in U.S. Pat.No. 5,576,374.

The term "interpolymer" is used herein to indicate a polymer wherein atleast two different monomers are polymerized to make the interpolymer.

The above-mentioned interpolymer(s) suitable in the filled polymercomposition of the present invention are thermoplastic, that means theymay be molded or otherwise shaped and reprocessed at temperatures abovetheir melting or softening point. They are not cross-linked to asubstantial degree, which means that the filled polymer compositions ofthe present invention do not contain more than 0.4 percent, preferablynot more than 0.2 percent, more preferably not more than 0.05 percent ofa cross-linking agent, based on the weight of the interpolymer(s). Mostpreferably, the filled polymer compositions of the present invention donot contain any measurable amount of a cross-linking agent.

The interpolymers employed in the present invention include, but are notlimited to substantially random interpolymers prepared by polymerizingone or more α-olefin monomers with one or more vinylidene aromaticmonomers and/or one or more hindered aliphatic or cycloaliphaticvinylidene monomers, and optionally with other polymerizableethylenically unsaturated monomer(s).

Suitable α-olefin monomers include, for example, α-olefin monomerscontaining from 2 to about 20, preferably from 2 to about 12, morepreferably from 2 to about 8 carbon atoms. Preferred such monomersinclude ethylene, propylene, butene-1, 4-methyl-1-pentene, hexene-1 andoctene-1. Most preferred are ethylene or a combination of ethylene withC₂₋₆ -α-olefins. These α-olefins do not contain an aromatic moiety.

Suitable vinylidene aromatic monomers which can be employed to preparethe interpolymers employed in the filled polymer compositions of thepresent invention include, for example, those represented by thefollowing formula: ##STR1## wherein R¹ is selected from the group ofradicals consisting of hydrogen and alkyl radicals containing from 1 toabout 4 carbon atoms, preferably hydrogen or methyl; each R² isindependently selected from the group of radicals consisting of hydrogenand alkyl radicals containing from 1 to about 4 carbon atoms, preferablyhydrogen or methyl; Ar is a phenyl group or a phenyl group substitutedwith from 1 to 5 substituents selected from the group consisting ofhalo, C₁₋₄ -alkyl, and C₁₋₄ -haloalkyl; and n has a value from zero toabout 4, preferably from zero to 2, most preferably zero. Exemplarymonovinylidene aromatic monomers include styrene, vinyl toluene,α-methylstyrene, t-butyl styrene, chlorostyrene, including all isomersof these compounds, and the like. Particularly suitable such monomersinclude styrene and lower alkyl- or halogen-substituted derivativesthereof. Preferred monomers include styrene, a-methyl styrene, the loweralkyl- (C₁ -C₄) or phenyl-ring substituted derivatives of styrene, suchas for example, ortho-, meta-, and para-methylstyrene, the ringhalogenated styrenes, para-vinyl toluene or mixtures thereof, and thelike. A more preferred aromatic monovinylidene monomer is styrene.

By the term "hindered aliphatic or cycloaliphatic vinylidene monomers",it is meant addition polymerizable vinylidene monomers corresponding tothe formula: ##STR2## wherein A¹ is a sterically bulky, aliphatic orcycloaliphatic substituent of up to 20 carbons, R¹ is selected from thegroup of radicals consisting of hydrogen and alkyl radicals containingfrom 1 to about 4 carbon atoms, preferably hydrogen or methyl; each R²is independently selected from the group of radicals consisting ofhydrogen and alkyl radicals containing from 1 to about 4 carbon atoms,preferably hydrogen or methyl; or alternatively R¹ and A¹ together forma ring system. By the term "sterically bulky" is meant that the monomerbearing this substituent is normally incapable of additionpolymerization by standard Ziegler-Natta polymerization catalysts at arate comparable with ethylene polymerizations. α-olefin monomerscontaining from 2 to about 20 carbon atoms and having a linear aliphaticstructure such as propylene, butene-1, hexene-1 and octene-1 are notconsidered as hindered aliphatic monomers. Preferred hindered aliphaticor cycloaliphatic vinylidene compounds are monomers in which one of thecarbon atoms bearing ethylenic unsaturation is tertiary or quaternarysubstituted. Examples of such substituents include cyclic aliphaticgroups such as cyclohexyl, cyclohexenyl, cyclooctenyl, or ring alkyl oraryl substituted derivatives thereof, tert-butyl, norbornyl, and thelike. Most preferred hindered aliphatic or cycloaliphatic vinylidenecompounds are the various isomeric vinyl-ring substituted derivatives ofcyclohexene and substituted cyclohexenes, and 5-ethylidene-2-norbornene.Especially suitable are 1-, 3-, and 4-vinylcyclohexene.

The interpolymers of one or more α-olefins and one or moremonovinylidene aromatic monomers and/or one or more hindered aliphaticor cycloaliphatic vinylidene monomers employed in the present inventionare substantially random polymers. These interpolymers usually containfrom about 0.5 to about 65, preferably from about 1 to about 55, morepreferably from about 2 to about 50, most preferably from about 20 toabout 50 mole percent of at least one vinylidene aromatic monomer and/orhindered aliphatic or cycloaliphatic vinylidene monomer and from about35 to about 99.5, preferably from about 45 to about 99, more preferablyfrom about 50 to about 98, most preferably from about 50 to about 80mole percent of at least one aliphatic α-olefin having from 2 to about20 carbon atoms.

Other optional polymerizable ethylenically unsaturated monomer(s)include strained ring olefins such as norbornene and C₁₋₁₀ alkyl orC₆₋₁₀ aryl substituted norbornenes, with an exemplary interpolymer beingethylene/styrene/norbornene.

The number average molecular weight (Mn) of the interpolymers is usuallygreater than about 5,000, preferably from about 20,000 to about1,000,000, more preferably from about 50,000 to about 500,000. The meltindex I₂ according to ASTM D 1238 Procedure A, condition E, generally isfrom about 0.01 to about 50 g/10 min., preferably from about 0.01 toabout 20 g/10 min., more preferably from about 0.1 to about 10 g/10min., and most preferably from about 0.5 to about 5 g/10 min. The glasstransition temperature (Tg) of the interpolymers is preferably fromabout -40° C. to about +35° C., preferably from about 0° C. to about+30° C., most preferably from about +10° C. to about +25° C., measuredaccording to differential mechanical scanning (DMS).

Polymerizations and unreacted monomer removal at temperatures above theautopolymerization temperature of the respective monomers may result information of some amounts of homopolymer polymerization productsresulting from free radical polymerization. For example, while preparingthe substantially random interpolymer, an amount of atactic vinylidenearomatic homopolymer may be formed due to homopolymerization of thevinylidene aromatic monomer at elevated temperatures. The presence ofvinylidene aromatic homopolymer is in general not detrimental for thepurposes of the present invention and can be tolerated. The vinylidenearomatic homopolymer may be separated from the interpolymer, if desired,by extraction techniques such as selective precipitation from solutionwith a non solvent for either the interpolymer or the vinylidenearomatic homopolymer. For the purpose of the present invention it ispreferred that no more than 20 weight percent, preferably less than 15weight percent based on the total weight of the interpolymers ofvinylidene aromatic homopolymer is present.

The substantially random interpolymers may be modified by typicalgrafting, hydrogenation, functionalizing, or other reactions well knownto those skilled in the art. The polymers may be readily sulfonated orchlorinated to provide functionalized derivatives according toestablished techniques.

The substantially random interpolymers can be prepared as described inU.S. application Ser. No. 07/545,403 filed Jul. 3, 1990 (correspondingto EP-A-0,416,815) by James C. Stevens et al. and in allowed U.S.application No. 08/469,828, filed Jun. 6, 1995, all of which areincorporated herein by reference in their entirety. Preferred operatingconditions for such polymerization reactions are pressures fromatmospheric up to 3,000 atmospheres and temperatures from -30° C. to200° C.

Examples of suitable catalysts and methods for preparing thesubstantially random interpolymers are disclosed in U.S. applicationSer. No. 07/545,403, filed Jul. 3, 1990 (corresponding to EP-A-416,815);U.S. application Ser. No. 547,718, filed Jul. 3, 1990 (corresponding toEP-A-468,651); U.S. application Ser. No. 07/702,475, filed May 20, 1991(corresponding to EP-A-514,828); U.S. application Ser. No. 07/876,268,filed May 1, 1992 (corresponding to EP-A-520,732); U.S. application Ser.No. 884,966, filed May 15, 1992 (corresponding to WO 93/23412); U.S.Pat. No. 5,374,696, filed Jan. 21, 1993; U.S. application Ser. No.34,434, filed Mar. 19, 1993 (corresponding to WO 94/01647); U.S.application Ser. No. 08/241,523, filed May 12, 1994, (corresponding toWO 94/06834 and EP 0,705,269); as well as U.S. Pat. Nos. 5,055,438;5,057,475; 5,096,867; 5,064,802; 5,132,380; and 5,189,192; 5,321,106;5,347,024; 5,350,723; 5,374,696; 5,399,635; 5,460,993 and 5,556,928 allof which patents and applications are incorporated herein by referencein their entirety.

The substantially random α-olefin/vinylidene aromatic interpolymers canalso be prepared by the methods described by John G. Bradfute et al.(W.R. Grace & Co.) in WO 95/32095; by R. B. Pannell (Exxon ChemicalPatents, Inc.) in WO 94/00500; and in Plastics Technology, page 25(September 1992), all of which are incorporated herein by reference intheir entirety.

Also suitable are the substantially random interpolymers which compriseat least one α-olefin/vinyl aromatic/vinyl aromatic/α-olefin tetraddisclosed in U.S. application Ser. No. 08/708,809, filed Sep. 4, 1996 byFrancis J. Timmers et al. These interpolymers contain additional signalswith intensities greater than three times the peak to peak noise. Thesesignals appear in the chemical shift range 43.75 to 44.25 ppm and 38.0to 38.5 ppm. Specifically, major peaks are observed at 44.1, 43.9 and38.2 ppm. A proton test NMR experiment indicates that the signals in thechemical shift region 43.75 to 44.25 ppm are methine carbons and thesignals in the region 38.0 to 38.5 ppm are methylene carbons.

In order to determine the carbon-¹³ NMR chemical shifts of theinterpolymers described, the following procedures and conditions areemployed. A five to ten weight percent polymer solution is prepared in amixture consisting of 50 volume percent 1,1,2,2-tetrachloroethane-d₂ and50 volume percent 0.10 molar chromium tris(acetylacetonate) in1,2,4-trichlorobenzene. NMR spectra are acquired at 130° C. using aninverse gated decoupling sequence, a 90° pulse width and a pulse delayof five seconds or more. The spectra are referenced to the isolatedmethylene signal of the polymer assigned at 30.000 ppm.

It is believed that these new signals are due to sequences involving twohead-to-tail vinyl aromatic monomer preceded and followed by at leastone α-olefin insertion, e.g. an ethylene/styrene/styrene/ethylene tetradwherein the styrene monomer insertions of said tetrads occur exclusivelyin a 1,2 (head to tail) manner. It is understood by one skilled in theart that for such tetrads involving a vinyl aromatic monomer other thanstyrene and an α-olefin other than ethylene that the ethylene/vinylaromatic monomer/vinyl aromatic monomer/ethylene tetrad will give riseto similar carbon-¹³ NMR peaks but with slightly different chemicalshifts.

These interpolymers are prepared by conducting the polymerization attemperatures of from about -30° C. to about 250° C. in the presence ofsuch catalysts as those represented by the formula ##STR3## wherein:each Cp is independently, each occurrence, a substitutedcyclopentadienyl group π-bound to M; E is C or Si; M is a group IVmetal, preferably Zr or Hf, most preferably Zr; each R is independently,each occurrence, H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl,containing up to about 30 preferably from 1 to about 20 more preferablyfrom 1 to about 10 carbon or silicon atoms; each R' is independently,each occurrence, H, halo, hydrocarbyl, hyrocarbyloxy, silahydrocarbyl,hydrocarbylsilyl containing up to about 30, preferably from 1 to about20, more preferably from 1 to about 10, carbon or silicon atoms or twoR' groups together can be a C₁₋₁₀ hydrocarbyl substituted 1,3-butadiene;m is 1 or 2; and optionally, but preferably in the presence of anactivating cocatalyst, such as tris(pentafluorophenyl) borane ormethylalumoxane (MAO). Particularly suitable substitutedcyclopentadienyl groups include those illustrated by the formula:##STR4## wherein each R is independently, each occurrence, H,hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up toabout 30 preferably from 1 to about 20 more preferably from 1 to about10 carbon or silicon atoms or two R groups together form a divalentderivative of such group. Preferably, R independently each occurrence is(including where appropriate all isomers) hydrogen, methyl, ethyl,propyl, butyl, pentyl, hexyl, benzyl, phenyl or silyl or (whereappropriate) two such R groups are linked together forming a fused ringsystem such as indenyl, fluorenyl, tetrahydroindenyl,tetrahydrofluorenyl, or octahydrofluorenyl.

Particularly preferred catalysts include, for example,racemic-(dimethylsilanediyl(2-methyl-4-phenylindenyl))zirconiumdichloride,racemic-(dimethylsilanediyl(2-methyl-4-phenylindenyl))zirconium1,4-diphenyl-1,3-butadiene,racemic-(dimethylsilanediyl(2-methyl-4-phenylindenyl))zirconium di-C1-4alkyl, racemic-(dimethylsilanediyl(2-methyl-4-phenylindenyl))zirconiumdi-C1-4 alkoxide, or any combination thereof and the like.

Further preparative methods for the interpolymer component (A) of thepresent invention have been described in the literature. Longo andGrassi (Makromol. Chem., Volume 191, pages 2387 to 2396 [1990]) andD'Anniello et al. (Journal of Applied Polymer Science, Volume 58, pages1701 to 1706 [1995]) reported the use of a catalytic system based onmethylalumoxane (MAO) and cyclopentadienyltitanium trichloride (CpTiCl₃)to prepare an ethylene-styrene copolymer. Xu and Lin (Polymer Preprints,Am. Chem. Soc., Div. Polym. Chem., volume 35, pages 686, 687 [1994])have reported copolymerization using a MgCl₂ /TiCl₄ /NdCl₃ /Al(iBu)₃catalyst to give random copolymers of styrene and propylene. Lu et al.(Journal of Applied Polymer Science, volume 53, pages 1453 to 1460[1994]) have described the copolymerization of ethylene and styreneusing a TiCl₄ /NdCl₃ / MgCl₂ /Al(Et)₃ catalyst. Sernetz and Mulhaupt,(Macromol. Chem. Phys., volume 197, pages 1071 to 1083 [1997]) havedescribed the influence of polymerization conditions on thecopolymerization of styrene with ethylene using Me₂ Si(Me₄ Cp)(N-tert-butyl)TiCl₂ /methylaluminoxane Ziegler-Natta catalysts. Themanufacture of α-olefin/vinyl aromatic monomer interpolymers such aspropylene/styrene and butene/styrene are described in U.S. Pat. No.5,244,996, issued to Mitsui Petrochemical Industries Ltd. All the abovemethods disclosed for preparing the interpolymer component areincorporated herein by reference.

The filled polymer composition of the present invention comprises

(A) from about 5 to about 90 percent, of one or more of theabove-described thermoplastic interpolymers, and

(B) from about 10 to about 95 percent of one or more inorganic fillers,the amounts of (A) and (B) being based on the total weight of (A) and(B).

The preferred amounts of inorganic filler depend on the desired end-useof the filled polymer compositions of the present invention.

For example, when producing floor, wall or ceiling tiles, the amount ofthe inorganic filler(s) (B) preferably is from about 50 to about 95percent, more preferably from about 70 to about 90 percent, based on thetotal weight of (A) and (B). On the other hand, when producing floor,wall or ceiling sheetings, the amount of the inorganic filler(s) (B)preferably is from about 10 to about 70 percent, more preferably fromabout 15 to about 50 percent, based on the total weight of (A) and (B).For several applications filler contents of from about 40 to about 90percent, more preferably from about 55 to about 85 percent, based on thetotal weight of (A) and (B), are preferred.

Preferred inorganic fillers are ionic inorganic materials. Preferredexamples of inorganic fillers are talc, calcium carbonate, aluminatrihydrate, glass fibers, marble dust, cement dust, clay, feldspar,silica or glass, fumed silica, alumina, magnesium oxide, magnesiumhydroxide, antimony oxide, zinc oxide, barium sulfate, aluminumsilicate, calcium silicate, titanium dioxide, titanates, glassmicrospheres or chalk. Of these fillers, barium sulfate, talc, calciumcarbonate, silica/glass, glass fibers, alumina and titanium dioxide, andmixtures thereof are preferred. The most preferred inorganic fillers aretalc, calcium carbonate, barium sulfate, glass fibers or mixturesthereof.

It has been surprisingly found that the α-olefin/vinylidene aromaticinterpolymers display a high compatibility with inorganic fillers. Thecomposition of the present invention may contain a coupling agent, suchas maleic anhydride grafted polyethylene or maleic anhydride graftedpolypropylene or a known silane/silicone coupling agent. However, thepresence of a coupling agent is not required, even if the filler contentis 55 weight percent or more. Even in the absence of a coupling agentfabricated articles of the present invention still exhibit good fillerholding and good solid state properties. This is unexpected, since manyof the above-mentioned α-olefin/vinylidene aromatic interpolymers arelargely unfunctionalized.

The filled polymer composition of the present invention may optionallycontain up to about 50 weight percent, preferably up to about 30 weightpercent, more preferably up to about 20 weight percent, most preferablyup to about 10 weight percent, of one or more further polymericcomponents, such as those described further below. However, the totalamount of the α-olefin/vinylidene aromatic interpolymer(s) (A) and theinorganic filler(s) (B) generally is at least about 50 percent,preferably at least about 70 percent, more preferably at least about 80percent and most preferably at least about 90 percent, based on thetotal weight of the filled polymer composition of the present invention.

Preferred additional, optional polymers are monovinylidene aromaticpolymers or styrenic block copolymers. The most preferred additional,optional polymers are homopolymers or interpolymers of aliphaticα-olefins having from 2 to about 20 carbon atoms or α-olefins havingfrom 2 to about 20 carbon atoms and containing polar groups.

Suitable monovinylidene aromatic polymers include homopolymers orinterpolymers of one or more monovinylidene aromatic monomers, orinterpolymers of one or more monovinylidene aromatic monomers and one ormore monomers interpolymerizable therewith other than an aliphaticα-olefin. Suitable monovinylidene aromatic monomers are represented bythe following formula: ##STR5## wherein R¹ and Ar have the meaningsstated in formula I above. Exemplary monovinylidene aromatic monomersare those listed under formula I above, particularly styrene.

Examples of suitable interpolymerizable comonomers other than amonovinylidene aromatic monomer include, for example, C₄ -C₆ conjugateddienes, especially butadiene or isoprene; ethylenically unsaturatednitriles such as acrylonitrile, methacrylonitrile, ethacrylonitrile,etc.; ethylenically unsaturated anhydrides such as maleic anhydride;ethylenically unsaturated amides such as acrylamide, methacrylamideetc.; ethylenically unsaturated carboxylic acids (both mono- anddifunctional) such as acrylic acid and methacrylic acid, etc.; esters(especially lower, e.g. C₁ -C₆, alkyl esters) of ethylenicallyunsaturated carboxylic acids such as methyl methacrylate, ethylacrylate, hydroxyethylacrylate, n-butyl acrylate or methacrylate,2-ethyl-hexylacrylate etc.; ethylenically unsaturated dicarboxylic acidimides such as N-alkyl or N-aryl maleimides such as N-phenyl maleimide,etc. Preferred monomers include maleic anhydride, methyl methacrylate,N-phenyl maleimide and acrylonitrile. In some cases it is also desirableto copolymerize a cross-linking monomer such as a divinyl benzene intothe monovinylidene aromatic polymer.

The polymers of monovinylidene aromatic monomers with otherinterpolymerizable comonomers preferably contain, polymerized therein,at least 50 percent by weight and, preferably, at least 90 percent byweight of one or more monovinylidene aromatic monomers.

Styrenic block polymers are also useful as an additional, optionalpolymer in the filled polymer composition of the present invention. Theterm "block copolymer" is used herein to mean elastomers having at leastone block segment of a hard polymer unit and at least one block segmentof a rubber monomer unit. However, the term is not intended to includethermoelastic ethylene interpolymers which are, in general, randompolymers. Preferred block copolymers contain hard segments of styrenictype polymers in combination with saturated or unsaturated rubbermonomer segments. The structure of the block copolymers useful in thepresent invention is not critical and can be of the linear or radialtype, either diblock or triblock, or any combination of thereof.

Suitable unsaturated block copolymers include those represented by thefollowing formulas:

    A--B--R(--B--A).sub.n

or

    A.sub.x --(BA--).sub.y --BA

wherein each A is a polymer block comprising a monovinylidene aromaticmonomer, preferably styrene, and each B is a polymer block comprising aconjugated diene, preferably isoprene or butadiene, and optionally amonovinylidene aromatic monomer, preferably styrene; R is the remnant ofa multifunctional coupling agent; n is an integer from 1 to about 5; xis zero or 1; and y is a number from zero to about 4.

Methods for the preparation of such block copolymers are known in theart. Suitable catalysts for the preparation of useful block copolymerswith unsaturated rubber monomer units include lithium based catalystsand especially lithium-alkyls. U.S. Pat. No. 3,595,942 describessuitable methods for hydrogenation of block copolymers with unsaturatedrubber monomer units to from block copolymers with saturated rubbermonomer units. The structure of the polymers is determined by theirmethods of polymerization. For example, linear polymers result bysequential introduction of the desired rubber monomer into the reactionvessel when using such initiators as lithium-alkyls or dilithiostilbeneand the like, or by coupling a two segment block copolymer with adifunctional coupling agent. Branched structures, on the other hand, maybe obtained by the use of suitable coupling agents having afunctionality with respect to the block copolymers with unsaturatedrubber monomer units of three or more. Coupling may be effected withmultifunctional coupling agents such as dihaloalkanes or alkenes anddivinyl benzene as well as with certain polar compounds such as siliconhalides, siloxanes or esters of monohydric alcohols with carboxylicacids. The presence of any coupling residues in the polymer may beignored for an adequate description of the block copolymers forming apart of the composition of this invention.

Suitable block copolymers having unsaturated rubber monomer unitsincludes, but is not limited to, styrene-butadiene (SB),styrene-isoprene(SI), styrene-butadiene-styrene (SBS),styrene-isoprene-styrene (SIS),α-methylstyrene-butadiene-a-methylstyrene andα-methylstyrene-isoprene-a-methylstyrene, and the like.

The styrenic portion of the block copolymer is preferably a polymer orinterpolymer of styrene and its analogs and homologs includingα-methylstyrene and ring-substituted styrenes, particularlyring-methylated styrenes. The preferred styrenics are styrene andα-methylstyrene, and styrene is particularly preferred.

Block copolymers with unsaturated rubber monomer units may comprisehomopolymers of butadiene or isoprene or they may comprise copolymers ofone or both of these two dienes with a minor amount of styrenic monomer.

Preferred block copolymers with saturated rubber monomer units compriseat least one segment of a styrenic unit and at least one segment of anethylene-butene or ethylene-propylene copolymer. Preferred examples ofsuch block copolymers with saturated rubber monomer units includestyrene/ethylene-butene copolymers, styrene/ethylene-propylenecopolymers, styrene/ethylene-butene/styrene (SEBS) copolymers,styrene/ethylene-propylene/styrene (SEPS) copolymers, and the like.

Hydrogenation of block copolymers with unsaturated rubber monomer unitsis preferably effected by use of a catalyst comprising the reactionproducts of an aluminum alkyl compound with nickel or cobaltcarboxylates or alkoxides under such conditions as to substantiallycompletely hydrogenate at least 80 percent of the aliphatic double bondswhile hydrogenating no more than about 25 percent of the styrenicaromatic double bonds. Preferred block copolymers are those where atleast 99 percent of the aliphatic double bonds are hydrogenated whileless than 5 percent of the aromatic double bonds are hydrogenated.

The proportion of the styrenic blocks is generally between about 8 and65 percent by weight of the total weight of the block copolymer.Preferably, the block copolymers contain from 10 to 35 weight percent ofstyrenic block segments and from 90 to 65 weight percent of rubbermonomer block segments, based on the total weight of the blockcopolymer.

The average molecular weights of the individual blocks may vary withincertain limits. In most instances, the styrenic block segments will havenumber average molecular weights in the range of about 5,000 to about125,000, preferably from about 7,000 to about 60,000 while the rubbermonomer block segments will have average molecular weights in the rangeof about 10,000 to about 300,000, preferably from about 30,000 to about150,000. The total average molecular weight of the block copolymer istypically in the range of about 25,000 to about 250,000, preferably fromabout 35,000 to about 200,000.

Further, the various block copolymers suitable for use in the presentinvention may be modified by graft incorporation of minor amounts offunctional groups, such as, for example, maleic anhydride by any of themethods well known in the art.

Block copolymers useful in the present invention are commerciallyavailable, such as, for example, supplied by Shell Chemical Companyunder the designation of KRATON™ and supplied by Dexco Polymers underthe designation of VECTOR™.

Preferred additional, optional polymers are homopolymers orinterpolymers of aliphatic α-olefins having from 2 to about 20,preferably 2 to about 18, more preferably 2 to about 12, carbon atoms orα-olefins having from 2 to about 20, preferably 2 to about 18, morepreferably 2 to about 12, carbon atoms and containing polar groups.

Suitable aliphatic α-olefin monomers which introduce polar groups intothe polymer include, for example, ethylenically unsaturated nitrilessuch as acrylonitrile, methacrylonitrile, ethacrylonitrile, etc.;ethylenically unsaturated anhydrides such as maleic anhydride;ethylenically unsaturated amides such as acrylamide, methacrylamideetc.; ethylenically unsaturated carboxylic acids (both mono- anddifunctional) such as acrylic acid and methacrylic acid, etc.; esters(especially lower, e.g. C₁ -C₆, alkyl esters) of ethylenicallyunsaturated carboxylic acids such as methyl methacrylate, ethylacrylate, hydroxyethylacrylate, n-butyl acrylate or methacrylate,2-ethyl-hexylacrylate etc.; ethylenically unsaturated dicarboxylic acidimides such as N-alkyl or N-aryl maleimides such as N-phenyl maleimide,etc. Preferably such monomers containing polar groups are acrylic acid,vinyl acetate, maleic anhydride and acrylonitrile. Halogen groups whichcan be included in the polymers from aliphatic α-olefin monomers includefluorine, chlorine and bromine; preferably such polymers are chlorinatedpolyethylenes (CPEs) or polyvinyl chloride. Preferred olefinic polymersfor use in the present invention are homopolymers or interpolymers of analiphatic, including cycloaliphatic, α-olefin having from 2 to 18 carbonatoms. Suitable examples are homopolymers of ethylene or propylene, andinterpolymers of two or more α-olefin monomers. Other preferred olefinicpolymers are interpolymers of ethylene and one or more other α-olefinshaving from 3 to 8 carbon atoms. Preferred comonomers include 1-butene,4-methyl-1-pentene, 1-hexene, and 1-octene. The olefinic polymer mayalso contain, in addition to the a-olefin, one or more non-aromaticmonomers interpolymerizable therewith. Such additionalinterpolymerizable monomers include, for example, C₄ -C₂₀ dienes,preferably, butadiene or 5 ethylidene-2-norbornene. The olefinicpolymers can be further characterized by their degree of long or shortchain branching and the distribution thereof.

One class of olefinic polymers is generally produced by a high pressurepolymerization process using a free radical initiator resulting in thetraditional long chain branched low density polyethylene (LDPE). LDPEemployed in the present composition usually has a density of less than0.94 g/cc (ASTM D 792) and a melt index of from 0.01 to 100, andpreferably from 0.1 to 50 grams per 10 minutes (as determined by ASTMTest Method D 1238, condition I).

Another class is the linear olefin polymers which have an absence oflong chain branching, as the traditional linear low density polyethylenepolymers (heterogeneous LLDPE) or linear high density polyethylenepolymers (HDPE) made using Ziegler polymerization processes (forexample, U.S. Pat. No. 4,076,698 (Anderson et al.), sometimes calledheterogeneous polymers.

HDPE consists mainly of long linear polyethylene chains. The HDPEemployed in the present composition usually has a density of at least0.94 grams per cubic centimeter (g/cc) as determined by ASTM Test MethodD 1505, and a melt index (ASTM-1238, condition I) in the range of from0.01 to 100, and preferably from 0.1 to 50 grams per 10 minutes.

The heterogeneous LLDPE employed in the present composition generallyhas a density of from 0.85 to 0.94 g/cc (ASTM D 792), and a melt index(ASTM-1238, condition I) in the range of from 0.01 to 100, andpreferably from 0.1 to 50 grams per 10 minutes. Preferably the LLDPE isan interpolymer of ethylene and one or more other α-olefins having from3 to 18 carbon atoms, more preferably from 3-8 carbon atoms. Preferredcomonomers include 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.

A further class is that of the uniformly branched or homogeneouspolymers (homogeneous LLDPE). The homogeneous polymers contain no longchain branches and have only branches derived from the monomers (ifhaving more than two carbon atoms). Homogeneous polymers include thosemade as described in U.S. Pat. No. 3,645,992 (Elston), and those madeusing single-site catalysts in a reactor having relatively high olefinconcentrations [as described in U.S. Pat. Nos. 5,026,798 and 5,055,438(Canich)]. The uniformly branched/homogeneous polymers are thosepolymers in which the comonomer is randomly distributed within a giveninterpolymer molecule and wherein the interpolymer molecules have asimilar ethylene/comonomer ratio within that interpolymer.

The homogeneous LLDPE employed in the present composition generally hasa density of from 0.85 to 0.94 g/cc (ASTM D 792), and a melt index(ASTM-1238, condition I) in the range of from 0.01 to 100, andpreferably from 0.1 to 50 grams per 10 minutes. Preferably the LLDPE isan interpolymer of ethylene and one or more other α-olefins having from3 to 18 carbon atoms, more preferably from 3-8 carbon atoms. Preferredcomonomers include 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.

Further, there is the class of substantially linear olefin polymers(SLOP) that may advantageously be used in component (B) of the blends ofthe present invention. These polymers have a processability similar toLDPE, but the strength and toughness of LLDPE. Similar to thetraditional homogeneous polymers, the substantially linearethylene/α-olefin interpolymers have only a single melting peak, asopposed to traditional Ziegler polymerized heterogeneous linearethylene/α-olefin interpolymers which have two or more melting peaks(determined using differential scanning calorimetry). Substantiallylinear olefin polymers are disclosed in U.S. Pat. Nos. 5,380,810;5,272,236 and 5,278,272 which are incorporated herein by reference.

The density of the SLOP as measured in accordance with ASTM D-792 isgenerally from 0.85 g/cc to 0.97 g/cc, preferably from 0.85 g/cc to0.955 g/cc, and especially from 0.85 g/cc to 0.92 g/cc.

The melt index, according to ASTM D-1238, Condition 190° C./2.16 kg(also known as I₂), of the SLOP is generally from 0.01 g/10 min. to 1000g/10 min., preferably from 0.01 g/10 min. to 100 g/10 min., andespecially from 0.01 g/10 min. to 10 g/10 min.

Also, included are the ultra low molecular weight ethylene polymers andethylene/α-olefin interpolymers described in the WO patent applicationno. 97/01181 entitled Ultra-low Molecular Weight Polymers, filed on Jan.22, 1997, which is incorporated herein by reference. Theseethylene/α-olefin interpolymers have I₂ melt indices greater than 1,000,or a number average molecular weight (Mn) less than 11,000.

The more preferred homopolymers or interpolymers of aliphatic α-olefinshaving from 2 to about 20 carbon atoms and optionally containing polargroups are homopolymers of ethylene; homopolymers of propylene,copolymers of ethylene and at least other α-olefin containing from 4 toabout 8 carbon atoms; copolymers of propylene and at least otherα-olefin containing from 4 to about 8 carbon atoms; copolymers ofethylene and at least one of acrylic acid, vinyl acetate, maleicanhydride or acrylonitrile; copolymers of propylene and at least one ofacrylic acid, vinyl acetate, maleic anhydride or acrylonitrile; andterpolymers of ethylene, propylene and a diene. Especially preferred areLDPE, HDPE, heterogeneous and homogeneous LLDPE, SLOP, polypropylene(PP), especially isotactic polypropylene and rubber-toughenedpolypropylenes, or ethylene-propylene interpolymers (EP), orethylene-vinyl acetate copolymers, or ethylene-acrylic acid copolymers,or any combination thereof.

The filled polymer composition of the present invention may contain oneor more additives, for example antioxidants, such as hindered phenols orphosphites; light stabilizers, such as hindered amines; plasticizers,such as dioctylphthalate or epoxidized soy bean oil; tackifiers, such asknown hydrocarbon tackifiers; waxes, such as polyethylene waxes;processing aids, such as oils, stearic acid or a metal salt thereof;crosslinking agents, such as peroxides or silanes; colorants or pigmentsto the extent that they do not interfere with desired physicalproperties of the filled polymer composition of the present invention.The additives are employed in functionally equivalent amounts known tothose skilled in the art, generally in amounts of up to about 30,preferably from about 0.01 to about 5, more preferably from about 0.02to about 1 percent by weight, based upon the total weight of the filledpolymer composition.

The filled polymer compositions can be compounded by any convenientmethod, such as dry blending of interpolymer(s), the filler(s) andoptional additives and subsequently melt mixing, either directly in theextruder used to make the finished article, or by pre-melt mixing in aseparate extruder (e.g., a Banbury mixer). Dry blends of thecompositions can also be directly injection molded without pre-meltmixture.

The blends can be processed to fabricated articles by any suitable meansknown in the art. For example, the filled polymer composition can beprocessed to films or sheets or to one or more layers of a multilayeredstructure by know processes, such as calendering, blowing, casting or(co-)extrusion processes. Injection molded, compression molded, extrudedor blow molded parts can also be prepared from the filled polymercompositions of the present invention. Alternatively, the filled polymercompositions can be processed to foams or fibers. Useful temperaturesfor processing the interpolymer(s) in combination with the filler(s) andoptional additives to the fabricated articles generally are from about100° C. to about 300° C., preferably from about 120° C. to about 250°C., more preferably from about 140° C. to about 200° C.

The fabricated articles of the present invention may be foamed. The foamlayer may be produced by an extrusion process or from expandable orfoamable particles, moldable foam particles, or beads from which a sheetis formed by expansion and/or coalescing and welding of those particles.

The foam structure may be made by a conventional extrusion foamingprocess. The structure is generally prepared by heating a polymermaterial to form a plasticized or melt polymer material, incorporatingtherein a known blowing agent to form a foamable gel, and extruding thegel through a die to form the foam product. Prior to mixing with theblowing agent, the polymer material is heated to a temperature at orabove its glass transition temperature or melting point. The blowingagent may be incorporated or mixed into the melt polymer material by anymeans known in the art such as with an extruder, mixer or blender. Theblowing agent is mixed with the melt polymer material at an elevatedpressure sufficient to prevent substantial expansion of the melt polymermaterial and to generally disperse the blowing agent homogeneouslytherein. Optionally, a nucleator may be blended in the polymer melt ordry blended with the polymer material prior to plasticizing or melting.The foamable gel is typically cooled to a lower temperature to optimizephysical characteristics of the foam structure. The gel is then extrudedor conveyed through a die of desired shape to a zone of reduced or lowerpressure to form the foam structure. The die can have a substantiallyrectangular orifice to produce a sheet of the desired width and height.Alternatively, the die can have multiple orifices to produce polymerstrands which can be cut to beads. The zone of lower pressure is at apressure lower than that in which the foamable gel is maintained priorto extrusion through the die. The lower pressure may be superatmosphericor subatmospheric (vacuum), but is preferably at an atmospheric level.

The foam structure may also be formed into foam beads suitable formolding into articles. To make the foam beads, discrete resin particlessuch as granulated resin pellets are suspended in a liquid medium inwhich they are substantially insoluble such as water; impregnated with ablowing agent by introducing the blowing agent into the liquid medium atan elevated pressure and temperature in an autoclave or other pressurevessel; and rapidly discharged into the atmosphere or a region ofreduced pressure to expand to form the foam beads. This process is welltaught in U.S. Pat. Nos. 4,379,859 and 4,464,484, which are incorporatedherein by reference.

The foam beads may then be molded by any means known in the art, such ascharging the foam beads to the mold, compressing the mold to compressthe beads, and heating the beads such as with steam to effect coalescingand welding of the beads to form the article. Optionally, the beads maybe impregnated with air or other blowing agent at an elevated pressureand temperature prior to charging to the mold. Further, the beads may beheated prior to charging. The foam beads may then be molded to sheets bya suitable molding method known in the art. Some of the methods aretaught in U.S. Pat. Nos. 3,504,068 and 3,953,558.

Various additives may be incorporated in the foam structure, such asstability control agents, nucleating agents, pigments, antioxidants,acid scavengers, ultraviolet absorbers, flame retardants, processingaids or extrusion aids. Some of the additives are described in moredetail above.

Fabricated articles of the present invention which are made from filledpolymer compositions comprising one or more thermoplastic interpolymersand one or more inorganic fillers in the above-mentioned weight ratioshave a substantially improved hardness and tensile modulus whilegenerally maintaining good elongation properties, such as elongation atbreak, stress at break and energy at break, as compared to fabricatedarticles made from one or more corresponding thermoplastic interpolymerswithout inclusion of a filler. Furthermore, the fabricated articles ofthe present invention generally have good thermal resistance and,depending on the type of filler, improved ignition resistance.

The filled polymer compositions of the present invention can readily beextruded onto a substrate. Alternatively the filled polymer compositionsof the present invention can be extruded, milled, or calendered asunsupported films or sheets, for example for producing floor tiles, walltiles, floor sheeting, wall coverings, or ceiling coverings. They areparticularly useful as sound insulating or energy absorbing layers,films, sheets or boards. Films, sheets or boards of a wide thicknessrange can be produced. Depending on the intended end-use, usefulthicknesses generally are from about 0.5 to about 20 mm, preferably fromabout 1 to about 10 mm. Alternatively, injection molded parts or blowmolded articles, such as toys, containers, building and constructionmaterials, automotive components, and other durable goods can beproduced from the filled polymer compositions of the present invention.

The following examples are provided to illustrate the present invention.The examples are not intended to limit the scope of the presentinvention and they should not be so interpreted. Amounts are in weightparts or weight percentages unless otherwise indicated.

TESTING

The properties of the polymers and blends are determined by thefollowing test procedures.

Melt Index (MI) is determined by ASTM D-1238 (1979), Condition E (190°C.; 2.16 kg).

Tensile strength, secant modulus, and elongation properties are measuredusing ASTM D 638, Type C. Elongation at break, stress at break andenergy at break are measured at a strain rate of 5 min⁻¹.

Flexural modulus is measured using ASTM D 790-95A.

Hardness is measured using a Hardness Tester for Shore A and D accordingto DIN 53505.

Tabor abrasion is measured according to ASTM F-510.

Scratch testing is carried out using an Erichson Universal ScratchTester equipped with a 90°-180 μm diameter stylus. A load of 0.1 to 1.0N is applied to this stylus, and the resulting scratch width is measuredafter 30 days by a Perthen Surface Profiler. Scratch width and depth isexpressed in micrometers.

For indentation testing, ASTM F 142-93 (Standard Test Method forIndentation of Resilient Floor-McBurney Test) and a modified test isused. In the modified test, a 140 lb. (64 kg) load is applied via a 4.5mm diameter cylindrical foot. The load is applied for 10 minutes and theinitial indentation is measured. The residual indentation is measuredafter 60 minutes. For the modified test, indentations are reported as aper cent of initial plaque thickness. For residual indentation, thesample is given a "fail" rating if the cylindrical indent footpermanently cuts and damages the surface.

Thermal transition temperatures are measured with differential scanningcalorimetry (DSC) and dynamic mechanical spectroscopy (DMS).

Preparation of Ethylene/Styrene Interpolymers ESI-1, ESI-2 and ESI-4

Reactor Description

The single reactor used is a 6 gallon (22.7 L), oil jacketed, Autoclavecontinuously stirred tank reactor (CSTR). A magnetically coupledagitator with Lightning A-320 impellers provides the mixing. The reactorruns liquid full at 475 psig (3,275 kPa). Process flow is in the bottomand out the top. A heat transfer oil is circulated through the jacket ofthe reactor to remove some of the heat of reaction. After the exit fromthe reactor a micromotion flow meter is arranged that measures flow andsolution density. All lines on the exit of the reactor are traced with50 psi (344.7 kPa) steam and insulated.

Procedure

Ethylbenzene solvent is supplied to the mini-plant at 30 psig (207 kPa).The feed to the reactor is measured by a Micro-Motion mass flow meter. Avariable speed diaphragm pump controls the feed rate. At the dischargeof the solvent pump a side stream is taken to provide flush flows forthe catalyst injection line (1 lb/hr (0.45 kg/hr)) and the reactoragitator (0.75 lb/hr (0.34 kg/hr)). These flows are measured bydifferential pressure flow meters and controlled by manual adjustment ofmicro-flow needle valves. Uninhibited styrene monomer is supplied to themini-plant at 30 psig (207 kpa). The feed to the reactor is measured bya Micro-Motion mass flow meter. A variable speed diaphragm pump controlsthe feed rate. The styrene stream is mixed with the remaining solventstream. Ethylene is supplied to the mini-plant at 600 psig (4,137 kPa).The ethylene stream is measured by a Micro-Motion mass flow meter justprior to the Research valve controlling flow. A Brooks flowmeter/controllers is used to deliver hydrogen into the ethylene streamat the outlet of the ethylene control valve. The ethylene/hydrogenmixture is combined with the solvent/styrene stream at ambienttemperature. The temperature of the solvent/monomer as it enters thereactor is reduced to about 5° C. by an exchanger with -5° C. glycol onthe jacket. This stream enters the bottom of the reactor. The threecomponent catalyst system and its solvent flush also enter the reactorat the bottom but through a different port than the monomer stream. Forpreparing ESI-1, ESI-2 and ESI-4,(t-butylamido)dimethyl(tetramethylcyclopentadienyl)silanetitanium (II)1,3-pentadiene is used as a titanium catalyst and modifiedmethylaluminoxane Type 3A (MMAO-3A, commercially available from Akzo) isused as a second catalyst component. Boron cocatalysts used aretris(pentafluorophenyl)borane (for preparing ESI-1 and ESI-2) orbis-hydrogenated tallowalkyl methylammoniumtetrakis(pentafluorophenyl)borate respectively (for preparing ESI-4).For preparing ESI-1, the molar ratio between the boron cocatalyst andthe titanium catalyst is 3:1 and the molar ratio between MMAO-3A and thetitanium catalyst is 8:1. For preparing ESI-2 and ESI-4, the molar ratiobetween the boron cocatalyst and the titanium catalyst is 2:1 and themolar ratio between MMAO-3A and the titanium catalyst is 5:1.Preparation of the catalyst components has taken place in an inertatmosphere glove box. The diluted components are put in nitrogen paddedcylinders and charged to the catalyst run tanks in the process area.From these run tanks the catalyst is pressured up with piston pumps andthe flow is measured with Micro-Motion mass flow meters. These streamscombine with each other and the catalyst flush solvent just prior toentry through a single injection line into the reactor.

Polymerization is stopped with the addition of catalyst kill (watermixed with solvent) into the reactor product line after the micromotionflow meter measuring the solution density. Other polymer additives canbe added with the catalyst kill. A static mixer in the line providesdispersion of the catalyst kill and additives in the reactor effluentstream. This stream next enters post reactor heaters that provideadditional energy for the solvent removal flash. This flash occurs asthe effluent exits the post reactor heater and the pressure drops from475 psig (3,275 kPa) down to about 250 mm of pressure absolute at thereactor pressure control valve. This flashed polymer enters a hot oiljacketed devolatilizer. Approximately 85 percent of the volatiles areremoved from the polymer in the devolatilizer. The volatiles exit thetop of the devolatilizer. The stream is condensed with a glycol jacketedexchanger, enters the suction of a vacuum pump and is discharged to aglycol jacket solvent and styrene/ethylene separation vessel. Solventand styrene are removed from the bottom of the vessel and ethylene fromthe top. The ethylene stream is measured with a Micro-Motion mass flowmeter and analyzed for composition. The measurement of vented ethyleneplus a calculation of the dissolved gasses in the solvent/styrene streamare used to calculate the ethylene conversion. The polymer separated inthe devolatilizer is pumped out with a gear pump to a ZSK-30devolatilizing vacuum extruder. The dry polymer exits the extruder as asingle strand. This strand is cooled as it is pulled through a waterbath. Excess water is blown from the strand with air and the strand ischopped into pellets with a strand chopper.

The monomer amounts and polymerization conditions are provided in Table1A. The polymer properties are provided in Table 1C further below.

                                      TABLE 1A                                    __________________________________________________________________________                                        Ethy-                                                                         lene                                      Reac-                      Styrene  reactor                                   tor     Solvent                                                                              Ethylene                                                                             Hydro-                                                                             Flow     Con-                                      Temp.   Flow   Flow   gen Flow                                                                           lb/h     version                                   ° C.                                                                           lb/hr                                                                            kg/hr                                                                             lb/hr                                                                            kg/hr                                                                             SCCM*                                                                              r    kg/hr                                                                             %                                         __________________________________________________________________________    ESI-1                                                                            62.1 10.4                                                                             4.72                                                                              1.2                                                                              0.54                                                                              20.0 12.0 5.45                                                                              77.7                                      ESI-2                                                                            84.3 17.6                                                                             7.99                                                                              1.9                                                                              0.86                                                                              27.6 20.6 9.35                                                                          75.6                                          ESI-4                                                                            76.0 16.4                                                                             7.44                                                                              1.2                                                                              0.54                                                                              7.0  10.0 4.54                                                                          90.5                                          __________________________________________________________________________     *cc/min., standardized to 1 atm (760 torr) and 0° C.              

Preparation of Ethylene/Styrene Interpolymers ESI-3, ESI-5, ESI-6 andESI-7

The Polymer is prepared in a 400 gallon (1514 liter) agitatedsemi-continuous batch reactor. The reaction mixture consists of about250 gallons (946 liter) of styrene and a solvent comprising a mixture ofcyclohexane (85 weight percent) and isopentane (15 weight percent).Prior to addition, solvent, styrene and ethylene are purified to removewater and oxygen. The inhibitor in the styrene is also removed. Inertsare removed by purging the vessel with ethylene. The vessel is thenpressure controlled to a set point with ethylene. Hydrogen is added tocontrol molecular weight. Temperature in the vessel is controlled toset-point by varying the jacket water temperature on the vessel. Priorto polymerization, the vessel is heated to the desired run temperatureand the catalyst components, i.e.(tert-butylamido)dimethyl(tetramethyl-η5-cyclopentadienyl)silanedimethyltitatium(IV) catalyst, CAS# 135072-62-7,Tris(pentafluorophenyl)boron, CAS# 001109-15-5, modifiedmethylaluminoxane Type 3A, CAS# 146905-79-5, are flow controlled, on amole ratio basis of 1/3/5 respectively, combined and added to thevessel. After starting, the polymerization is allowed to proceed withethylene supplied to the reactor as required to maintain vesselpressure. In some cases, hydrogen is added to the headspace of thereactor to maintain a mole ratio with respect to the ethyleneconcentration. At the end of the run, the catalyst flow is stopped,ethylene is removed from the reactor, about 1000 ppm of Irganox™ 1010antioxidant is then added to the solution and the polymer is isolatedfrom the solution. The resulting polymers are isolated from solution byeither stripping with steam in a vessel (in the case of ESI-3, ESI-6 andESI-7) or by use of a devolatilizing extruder (in the case of ESI-5). Inthe case of the steam stripped material, additional processing isrequired in extruder like equipment to reduce residual moisture and anyunreacted styrene.

The monomer amounts and polymerization conditions are provided in Table1B. The polymer properties are provided in Table 1C.

                                      TABLE 1B                                    __________________________________________________________________________                                Total                                                                              Run                                                                              Polymer                                   Solvent    Styrene                                                                             Pressure   H.sub.2                                                                            Time                                                                             in                                        Sample                                                                            loaded loaded Psi    Temp                                                                             Added                                                                              Hour                                                                             Solution                                  Number                                                                            lbs                                                                              kg  lbs                                                                              kg  g  kPa ° C.                                                                      Grams                                                                              s  Wt. %                                     __________________________________________________________________________    ESI-3                                                                             252                                                                              114 1320                                                                             600 40 276 60 23   6.5                                                                              18.0                                      ESI-5                                                                             1196                                                                             542 225                                                                              102 70 483 60 7.5  6.1                                                                              7.2                                       ESI-6                                                                             842                                                                              382 662                                                                              300 105                                                                              724 60 8.8  3.7                                                                              8.6                                       ESI-7                                                                             252                                                                              114 1320                                                                             599 42 290 60 0    2.8                                                                              11.5                                      __________________________________________________________________________

                  TABLE 1C                                                        ______________________________________                                                                           Styrene in                                                                    ethylene/                                                          Total %    styrene                                                  Melt      Styrene    Interpolymer                               Inter-                                                                              Tg      Index     (NMR)      (NMR)                                      polymer                                                                             ° C.                                                                           g/10 min  mol %  wt. % mol %  wt. %                             ______________________________________                                        ESI-1 na*     2.0       30.3   60.0  na*    na*                               ESI-2 na*     30.0      32.0   62.0  10.3   28.4                              ESI-3 25      1.8       46.1   74.8  43.4   72.7                              ESI-4 17      2.2       41.3   70.9  40.2   70.0                              ESI-5 -17.2   0.03      10.2   28.2  9.2    27.3                              ESI-6 -12.7   0.01      21.1   48.1  18.6   45.9                              ESI-7 24.2    0.18      48.7   76.7  43.6   74.2                              ______________________________________                                         *na = not analyzed                                                       

                  TABLE 2                                                         ______________________________________                                        Other Materials used in Examples                                                                           Melt                                                                          Index                                            Abbre-                       (gm/10  Density                                  viation                                                                             Product Name           min)    (gm/cc)                                  ______________________________________                                        ITP-1 AFFINITY ™ DSH 8501.00 POP                                                                        1.0     0.871                                          (ethylene-1-octene copolymer)                                           ITP-2 AFFINITY ™ DSH 1500.00                                                                            1.0     0.902                                          (ethylene-1-octene copolymer)                                           ITP-3 AFFINITY ™ SM 8400  30.0    0.871                                          (ethylene-1-octene copolymer)                                           ITP-4 AFFINITY ™ SM 1300  30.0    0.902                                          (ethylene-1-octene copolymer)                                           MAH   Dow XU-60769.04        2.5     0.955                                          (maleic anhydride graft polyethylene,                                         containing 1.0% maleic acid)                                            CaCO.sub.3                                                                          for Examples 1-25 obtained from                                               Pfizer ATF-40 (Ground limestone, 40 mesh)                               CaCO.sub.3                                                                          for Examples 26-48: Whingdale White                                           (average particle size 6 micron)                                        Talc  Owen Corning OC 187A-AA                                                 Oil   SHELLFLEX ™ 371                                                      ______________________________________                                    

EXAMPLES 1 TO 25

In Examples 1 to 25 plaques are prepared via the following steps: 1)Haake bowl mixing, 2) roll milling, and 3) compression molding intoplaques. A Haake mixer equipped with a Rheomix 3000 bowl is used. Allcomponents of the blend are added to the mixer, and the rotor isoperated at 190° C. and 40 rpm for 10 to 15 minutes. The material isthen dropped out of the Haake, and fed to a 6 inch diameter×12 inch wideFarrel two-roll mill set at 175° C. surface temperature. The sheet iseither taken off after a 180° wrap or is allowed to wrap 540° beforerelease. The sheet is then cut and compression molded into 3.175 mmthick×101.6 mm×101.6 mm plaques with a Pasadena Hydraulics Incorporated(PHI) press. The press is operated at 205° C. in a preheat mode atminimal pressure for 3 minutes, and is then pressured up to 15 tons for2 minutes. Plaques are then removed from the heat and cooled at 15 tonsfor 3 minutes.

Properties of the compression molded plaques are measured as indicatedabove.

Tables 3 and 4 list the compositions and resulting physical propertiesof Examples 1 to 23 according to the present invention and ofComparative Examples 24 and 25 for 60 percent filled and 85 percentfilled formulations, respectively.

                                      TABLE 3                                     __________________________________________________________________________    EXAMPLE #      1  2   3  4  5   6   7   8  9  10                              __________________________________________________________________________    COMPOSITION - weight percent                                                  CaCO3          60 60  60 60 60  60  60  60 60 60                              ESI-1          40                          36                                 ESI-3             40     32 36  28  20        36                              ESI-4                 40                20                                    Oil                      8                                                    ITP-1                       4   12  20  20                                    ITP-2                                                                         ITP-3                                                                         ITP-4                                                                         MAH                                        4  4                               PROPERTIES                                                                    Tensile Strength (MPa)                                                                       1.90                                                                             5.81                                                                              3.83                                                                             2.54                                                                             5.23                                                                              4.55                                                                              3.62                                                                              2.71                                                                             3.77                                                                             7.52                            2% Secant Mod (MPa)                                                                          19.50                                                                            87.45                                                                             32.12                                                                            15.12                                                                            58.50                                                                             61.83                                                                             60.83                                                                             38.94                                                                            26.94                                                                            502.62                          Flex Modulus (MPa)                                                                           30.88                                                                            514.69                                                                            41.34                                                                            40.20                                                                            196.90                                                                            198.41                                                                            139.48                                                                            45.69                                                                            37.43                                                                            111.04                          Elongation at break (%)                                                                      460                                                                              24.25                                                                             196                                                                              309.6                                                                            68.35                                                                             36.6                                                                              244 212                                                                              100.2                                                                            31.9                            Hardness-Shore D                                                                             35.6                                                                             75.2                                                                              56.2                                                                             50.6                                                                             71.6                                                                              86.4                                                                              48  36.6                                                                             40.6                                                                             70.6                            Hardness-Shore A                                                                             86 97.6                                                                              91.4                                                                             81.2                                                                             97.8                                                                              96.6                                                                              95  78.8                                                                             90.4                                                                             98                              Indentation-14 kg - 1 min (mil)                                                              24 13  14 19 15  18  20  14 21 14                              Indentation-14 kg - 10 min (mil)                                                             53 26  23 40 28  31  34  23 47 24                              Indentation-64 kg                                                                            76 19.8                                                                              61 68 31  41  74  67 78 24                              (% of thickness)                                                              Residual Indentation-64 kg (% of                                                             21 5.8 1.5                                                                              6.6.                                                                             5.1 5.8 20.7                                                                              14 fail                                                                             7.3                             thickness)                                                                    Scratch width (micron)                                                                       nt nt  nt nt nt  48  nt  nt nt 102                             Scratch depth (micron)                                                                       nt nt  nt nt nt  2.37                                                                              nt  nt nt 2.77                            Taber Abrasion (mg/100 rev)                                                                  0.60                                                                             3.92                                                                              2.88                                                                             1.46                                                                             .4.98                                                                             5.86                                                                              6.88                                                                              5.88                                                                             1.12                                                                             7.52                            __________________________________________________________________________     nt = not tested                                                          

Examples 1 to 8 illustrate that no additive or polymeric coupling agentis required to achieve good filler holding and solid state properties.The products of Examples 1 to 10 are useful as filled homogeneoussheets, such as floor coverings, or as an individual layer in aheterogeneous structure. The products of Examples 1 to 10 are especiallysuited for floor sheeting products.

                                      TABLE 4                                     __________________________________________________________________________    EXAMPLE #   11 12 13 14 15 16 17 18 19 20 21 22 23 24*                                                                              25*                     __________________________________________________________________________    COMPOSITION - weight                                                          CaCO3       85 85 85 85 85 85 85 85 85 85 85 85 85 85 85                      ESI-2       15                      7.5                                                                              7.5   13.5                             ESI-3          15    12 13.5                                                                             10.5                                                                             7.5                                                                              7.5            13.5                          ESI-4             15                      7.5                                 Oil                  3                                                        ITP-1                                                                         ITP-2                                                                         ITP-3                   1.5                                                                              4.5                                                                              7.5   7.5   7.5      13.5                       ITP-4                            7.5   7.5            13.5                    MAH                                          1.5                                                                              1.5                                                                              1.5                                                                              1.5                     PROPERTIES                                                                    Tensile Strength (MPa)                                                                    5.50                                                                             1.41                                                                             11.1                                                                             4.26                                                                             nt 8.41                                                                             6.06                                                                             13.4                                                                             4.42                                                                             9.61                                                                             6.39                                                                             6.30                                                                             2.26                                                                             5.77                                                                             11.8                    2% Secant Mod (MPa)                                                                       132                                                                              515                                                                              234                                                                              54 569                                                                              386                                                                              282                                                                              757                                                                              178                                                                              607                                                                              225                                                                              361                                                                              788                                                                              315                                                                              101                     Flex Modulus (Mpa)                                                                        182                                                                              170                                                                              273                                                                              77 210                                                                              120                                                                              660                                                                              170                                                                              235                                                                              153                                                                              277                                                                              110                                                                              227                                                                              587                                                                              272                     COMPOSITION - weight                                                          Elongation at break (%)                                                                   2.45                                                                             0.15                                                                             5.9                                                                              8.7   2.05                                                                             5.4                                                                              0.65                                                                             9.2                                                                              3.6                                                                              6.3                                                                              3.65                                                                             0.05                                                                             5  1.7                     Hardness-Shore D                                                                          87 85 82 63 83 73 65 74 53 66 63 70 78 57 70                      Hardness-Shore A                                                                          96 98 96 92 98 99 98 98 95 98 96 98 99 97 98                      Indentation-14 kg-1 min                                                                   12 4  5  14 5  8  10 5  14 6  8  8  4  8  4                       Indentation-14 kg-10                                                                      21 7  10 29 8  13 15 7  19 8  13 12 6  11 5                       Indentation-64 kg                                                                         71 4.1                                                                              9  61 4.8                                                                              nt 28 5.2                                                                              89 9.9                                                                              30 15.5                                                                             7.5                                                                              91 5.8                     (% of thickness)                                                              Residual Indentation-64                                                                   fail                                                                             1.7                                                                              0.7                                                                              11.8                                                                             2.1                                                                              2.5                                                                              6.9                                                                              0.8                                                                              fail                                                                             2.3                                                                              7.5                                                                              7.4                                                                              2.8                                                                              fail                                                                             1.6                     kg (% of thickness)                                                           Scratch width (micron)                                                                    77 77 59 64 56 73 80 79 69 nt nt 82 66 105                                                                              101                     Scratch depth (micron)                                                                    4.80                                                                             2.51                                                                             1.89                                                                             5.26                                                                             2.05                                                                             5.65                                                                             4.97                                                                             5.16                                                                             12.4                                                                             nt nt 7.93                                                                             3.46                                                                             9.07                                                                             6.19                    Taber Abrasion (mg/100                                                                    12.7                                                                             14.8                                                                             12.7                                                                             12.3                                                                             15.8                                                                             19.9                                                                             21.4                                                                             nt 18.6                                                                             17.4                                                                             21.7                                                                             18.2                                                                             nt 17.8                                                                             15.7                    __________________________________________________________________________     *Comparative Example                                                          *nt = not tested                                                         

The plaques of Examples 11 to 23 have a considerably higher high scratchresistance than the plaques of Comparative Examples 24 and 25.

Examples 11 to 21 illustrate that no additive or polymeric couplingagent is required to achieve good filler holding and solid stateproperties.

The plaque of Example 13 shows an exceptional combination of flexibilityand indentation resistance, and is particularly useful in or as a floortile product with good installability and good conformability to unevenand contoured surfaces.

The products of Examples 11 to 23 are useful as a filled homogeneoussheets, such as floor coverings, or as an individual layer in aheterogeneous structure. The products of Examples 11 to 23 areespecially suited for floor tile products.

EXAMPLES 26 TO 48

In Examples 26 to 48 plaques are produced as described in above inExamples 1 to 27 except that no roll milling process is applied and thedimensions of the plaques are 5 in×5 in×0.08 in (127 mm×127 mm×2.03 mm).

                                      TABLE 5                                     __________________________________________________________________________    EXAMPLE #   26 27 28 29 30 31 32 33*                                                                              34 35 36 37 38 39 40                      __________________________________________________________________________    COMPOSITION - weight                                                          CaCO3          50       20          20 50 80                                  talc              50       20                20 50                            glass fibers         50       20                   20 50                      ESI-5       100                                                                              50 50 50 80 80 80                                              ESI-6                            100                                                                              80 50 20 80 50 80 50                      PROPERTIES                                                                    Tensile Strength (MPa)                                                        2% Secant Mod (MPa)                                                           Flex Modulus (MPa)                                                                        20 69.6                                                                             233.7                                                                            804                                                                              33.8                                                                             64.8                                                                             293.1                                                                            7.6                                                                              9.7                                                                              17.9                                                                             168.9                                                                            15.9                                                                             75.2                                                                             246.8                                                                            1228                    Yield stress (MPa)                                                                        2  7  11 16                                                       Elongation (%) at break                                                                   378                                                                              320                                                                              102                                                                              7  341                                                                              347                                                                              178                                                                              147                                                                              581                                                                              581                                                                              21 602                                                                              503                                                                              25 7                       Stress at break (MPa)                                                                     34.3                                                                             17.1                                                                             12.2                                                                             11.4                                                                             30.2                                                                             32.7                                                                             12 2.9                                                                              15 8.8                                                                              7.7                                                                              16.2                                                                             8.6                                                                              5.8                                                                              19                      Energy at break (Nm)                                                                      145.1                                                                            158.7                                                                            59.7                                                                             3.5                                                                              162.7                                                                            179                                                                              84.1                                                                             12.2                                                                             105.8                                                                            93.6                                                                             6.8                                                                              154.6                                                                            153.2                                                                            5.4                                                                              5.4                     COMPOSITION - weight                                                          CaCO3          20 50 80                                                       talc                    20 50                                                 glass fibers                  20 50                                           ESI-7       100                                                                              80 50 20 80 50 80 50                                           PROPERTIES                                                                    Tensile Strength (MPa)                                                        2% Secant Mod (MPa)                                                           Flex Modulus (MPa)                                                                        594.4                                                                            2123                                                                             3161                                                                             5543                                                                             3827                                                                             5202                                                                             2417                                                                             6244.8                                       Yield stress (MPa)                                                                        6  17 22 34                                                       Elongation (%) at break                                                                   258                                                                              198                                                                              66 1  244                                                                              22 9  1                                            Stress at break (MPa)                                                                     21.6                                                                             17 13.7                                                                             34.3                                                                             22.9                                                                             26.4                                                                             27.2                                                                             57.7                                         Energy at break (Nm)                                                                      118                                                                              119.3                                                                            42 0.7                                                                              176.3                                                                            27.1                                                                             6.8                                                                              1.4                                          __________________________________________________________________________     *Comparative Example                                                          nt = not tested                                                          

What is claimed is:
 1. A filled polymer composition comprising(A) fromabout 5 to about 90 percent of one or more thermoplastic substantiallyrandom interpolymers prepared by polymerizing one or more α-olefinmonomers with one or more vinylidene aromatic monomers and/or one ormore hindered aliphatic or cycloaliphatic vinylidene monomers, andoptionally with other polymerizable ethylenically unsaturatedmonomer(s), and (B) from about 10 to about 95 percent of one or moreinorganic fillers, the amounts of (A) and (B) being based on the totalweight of (A) and (B).
 2. The filled polymer composition of claim 1wherein said one or more interpolymers contain one or more tetradsequences consisting of α-olefin/vinylidene aromatic monomer/vinylidenearomatic monomer/α-olefin insertions detectable by ¹³ C-NMR spectroscopywherein the monomer insertions of said tetrads occur exclusively in a1,2 (head to tail) manner.
 3. The filled polymer composition of claim 1wherein said one or more interpolymers contain interpolymerizedfromabout 0.5 to about 65 mole percent of one or more α-olefin monomers andfrom about 99.5 to about 35 mole percent of one or more vinylidenearomatic monomers and/or one or more hindered aliphatic orcycloaliphatic vinylidene monomers, and optionally other polymerizableethylenically unsaturated monomer(s).
 4. The filled polymer compositionof claim 1 wherein said one or more interpolymers containinterpolymerized from about 20 to about 50 mole percent of one or moreα-olefin monomers and from about 80 to about 50 mole percent of one ormore vinylidene aromatic monomers and/or one or more hindered aliphaticor cycloaliphatic vinylidene monomers, and optionally otherpolymerizable ethylenically unsaturated monomer(s).
 5. The filledpolymer composition of claim 1 wherein said one or more α-interpolymersis one or more interpolymers of ethylene and styrene.
 6. The filledpolymer composition of claim 1 wherein said one or more interpolymers isone or more interpolymers of styrene, ethylene and at least one otherα-olefin containing from 3 to about 8 carbon atoms.
 7. The filledpolymer composition of claim 1 comprising from about 40 to about 90percent of one or more inorganic fillers, based on the total weight ofthe interpolymers and the filler(s).
 8. The filled polymer compositionof claim 1 comprising from about 55 to about 85 percent of one or moreinorganic fillers, based on the total weight of the interpolymers andthe filler(s).
 9. The filled polymer composition of claim 1 comprisingone or more ionic inorganic fillers.
 10. The filled polymer compositionof claim 9 wherein the filler is talc, calcium carbonate, bariumsulfate, glass fibers or a mixture thereof.
 11. The filled polymercomposition of claim 1 wherein the total amount of the interpolymer(s)(A) and the inorganic filler(s) (B) is at least about 50 percent, basedon the total weight of the filled polymer composition.
 12. The filledpolymer composition of claim 1 wherein the total amount of theinterpolymers (A) and the inorganic filler(s) (B) is at least about 80percent, based on the total weight of the filled polymer composition.13. The filled polymer composition of claim 1 comprising up to about 50weight percent of one or more additional polymeric component(s), basedon the total weight of the filled polymer composition.
 14. A fabricatedarticle made from the polymer composition of claim
 1. 15. The fabricatedarticle of claim 14 in the shape of a film or sheet.
 16. The fabricatedarticle of claim 14 in the shape of a floor, wall or ceiling covering.17. The fabricated article of claim 14 in the form of a foam.
 18. Thefabricated article of claim 14 in the form of fibers.
 19. The fabricatedarticle of claim 14 made by injection molding, compression molding,extrusion or blow molding.
 20. A multilayered structure wherein at leastone layer is made from the polymer composition of claim 1.